This invention relates to a novel fibronectin-physiologically active substance complex and the preparation thereof. More particularly it relates to a method of preparing a fibronectin-physiologically active substance complex resulting from combining a fibronectin, which has a high affinity for a morbid part such as an injured tissue or a neoplastic cell proliferation site with a physiologically active substance capable of protecting and repairing these tissues and sites and the thus prepared complex.
It is a common practice to administer various physiologically active substances systemically to prevent the suppuration of a wounded site, to promote the repair of an inflamed site, and to destory cancer cells. In this case it is unavoidable at present to administer a large amount of the physiologically active substance in order to attain to a sufficient concentration to exert its effect.
Especially in the case of administering an antitumor substance, since the dose giving a manifest effect and that giving a manifest side effect are frequently in close proximity, the large-amount administration is often compelled to be discontinued owing to the manifestation of the side effect even when a promising
This invention relates to a novel fibronectin-physiologically active substance complex and the preparation thereof. More particularly it relates to a method of preparing a fibronectin-physiologically active substance complex resulting from combining a fibronectin which has a high affinity for a morbid part such as an injured tissue or a neoplastic cell proliferation site with a physiologically active substance capable of protecting and repairing these tissues and sites and thus prepared complex.
It is a common practice to administer various physiologically active substances systemically to prevent the suppuration of wounded site, to promote the repair of inflamed site, and to destroy the cancer cells. In this case it is unavoidable at present to administer a large amount of the physiologically active substance in order to attain to a sufficient concentration to exert its effect.
Especially in the case of administering an antitumor substance, since the dose gving a manifest effect and that giving a manifest side effect are frequently in close proximity, the large-amount administration is often compelled to be discontinued owing to the manifestation of the side effect even when a promising effect can be expected, leading thus to a fatal result. In order to avoid such situations, it is necessary to accumulate the physiologically active substance specifically in the morbid part as an injured tissue such as a wounded site and an inflamed site, or a neoplastic cell proliferation site.
The inventors have made intensive studies based on the idea that, in order to accumulate the physiologically active substance specifically in the local region, the remedy should be transported in a high concentration to the local region by using as a carrier a substance which has a high affinity for the morbid part as a wounded site, an inflamed site, and a neoplastic cell proliferation site.
An example of such a carrier is already known in the use of, for example, a cancer-specific antibody as the carrier of an antitumor substance. In this case, the specific accumulation does not take place unless the target cancer has an antigen which is specific to the antibody used as the carrier. Thus, this method has the disadvantage in that its effectiveness is exhibited only in very limited cases. There is no clear example of a carrier being used for an antibiotic. However, a straightforward example of a serious side effect caused by a large-amount administration required for acquiring an effective concentration is seen in the administration of chloramphenicol. Even in this case, it would be possible to avoid the side effect if the main effect can be manifested at a small dose. The same applies to an anti-inflammatory agent as to the antibiotic. Especially for these agents and substances, there exists no specificity like an antigen-antibody reaction in the morbid part, and hence no carrier has been found and no specific accumulation has been tried in the known art.